In the past, in denitrification of metal nitrates, aluminum nitrate has been added to waste solutions containing nitric acid and metal nitrates, such as sodium nitrate and radioactive salts, for example. In particular, waste solutions containing sodium nitrate have been mixed with aluminum nitrate in a direct kerosene fired bed calciner at about 500° C. In this process, the sodium nitrate and aluminum nitrate are converted to sodium aluminate and nitrogen oxides (commonly referred to as NOx, e.g., NO, NO2, and N2O3) according to the following formula:NaNO3+Al(NO3)3→NaAlO2+4NOx
Unfortunately, the above process requires a substantial amount of aluminum nitrate and is only about 70 percent effective in denitrifying the metal nitrates. Further, the nitrogen oxides that are produced during the reaction are wet-scrubbed, generating more nitrite/nitrate solution than the process began with. Also, problems of agglomeration have been experienced in the calciner due to melting in the bed. As such, a new process that requires less additive, is more efficient, more effective, less costly and more operationally available is needed in treating waste streams, and particular in treating waste streams including nitrogen-containing compounds such as nitrates, nitrites, and NOx compounds.